Compression riveter adjustable stop means



1366- 1949 H. R. FISCHER ,0

COMPRESSION RIVETER ADJUSTABLE STOP MEANS Original Filed Aug. 2, 1940 Patented Dec. 20, 1949 COMPBESSIONRIVETER ADJUSTABLE 's'roPMEans HQWald I L; F iseher, Detroit Mich., assignor to atic Tool Cbmpany, New 'Yoifk,

flriginal application. August 2,. 1940, semi No;

349320.. Divided-and this application January .2. .9 5,.S tie. N 65.:

This invention relates generaliy to ilpid operated. presses] for periorming rivetingjai dsimilar stroke adjuster fonc ntrolling ithe tent offseparation between the complementa dies or; t e working jaws during theinteryal between'sum cessive power strokes. Thissppneanonis' division of parent] application SerialNb. 349,820, filed August 2("1940'... which is now; Patent No, 2,389,661, granted Noveniherlzfl 1M5.

In'a device offthe classto which the present invention relates a working plunger is moved toward andv away f rom -a stationarydie, or through a compression and returnstroke, to: complete a single cycle of operation. The plunger is forced toward the stationary die by a power"piston1 ,actjing either directly "on theplunger or through intermediate pressure multiplying and; transmit.- ting elementsflwhile any yieldingmeahs'inay be used to return the plunger. 'The power piston reciprocates within a, cylinder, constructed as an integral part. oflthe tool assembly or locatedilfemotely therefrom, andmove nent of; the piston 1 Claiim Ql. m age is- 2 s a .trontend e oit s onl h wn in 1, with" a cover. plate removed andith'elower endl o f the stationary yoke. broken away.

' The inventionisshowri ernbodied"in a small riveting tool of the type adapted eithertp be mounted upon a pedestalfjfor useas "aflxedfmachine, or heldin thehands of the operator, for use as a portable tool. The tool is, further, of the class embodying, rivet set mechanismlpowerf mechanism and opera in; controls inasingle unitary structure, conn jctedj by a pressure fluid conducting hose line to a source of power. Referring to Fig. 1', the tool comprises several cooperating sect ris QY SIQb-IlliiitSj including a head I lijand a cylinder lj'l, intermediate thejhead Ill and. an end portion, or'fcasiiigffl to which is secured a yoke l3. Within the ead I11 are pressure fluid passages and controljvalves; whilelwithin the cyl index; I I,is a piston l4 having a? rod I5 secured thereto andextending throughone'endofthe cy1- is effected bypressure fiuid directedto alternate ends of the cylinder. at opposite. sides of the piston head. The means forcontrolling the flow of pressure fluid to the power eylinder is not de scribed in detail; in thiscase as it' is covered by the parent application aforesaid.

An object of the present; invention is to limit the separation of the W king dies to s uch space as may be necessar for "11'! sertion an'd 'ije'nioval' oi the work pieces, and thereby enabie theoprator more quickly and accuratelytoj-apply the tool to the rivets.

Another object is to permitthe clearaneespace hetweejn the dies or jaws to heregulat' simple adjustment. A'ccord i gly', featurepf'the invention is a return stroke regulator co a jstopelement adjustably it cepting movement of thew from the'stationaryfiaw'; e ahledafiwfll to permit the'p lung'er to complete arieturn stroke when desiredi 1 Gther objects and structuraldetails offthe in vention will be more apparent'fro'm the" following description when lteadi'in conjunction with the accompanying drawing, wherein:

Fig.1 is a view, partly in'lbh itudinal. section and partly in side elevation offa riyeting'jtjool embodying' the structureand mechanisrhmf the present invention and including an adjustable mechanism for limiting the movement of the working plunger away from the stationary die; and

inder into the end 'on l2; Fiiredfto'theouter end oftherodfls s plate l6biiurcatedto form a pair offarms lffiseeazlsofFig; 2). between which are supportedfa pair ofjrollers {8: The rollers l8 are arranged one above the other and theupper one engages the lower; surface of a guide block l9,. fixed within the casing I 2, while the lower one engages the upperedgef (if a lever'2l pivoted on astud 22 supportedfbetween' the sidewalls of casing 12, The lower edge: oftheiever 2| is fermedat its outer en dwith a projection 23 which overlies the upperferidfd fia downwardly extending plunger or movable jaw 24fmovablewithin a bushm 25 positionedin the upper end ofl the yoke la;

The lower endofthe plungerfllies above a die 26 set in the lowerjfjaw of' the yoke" l3 and the plun er reciprocates verticall'y'in a, movement toward and away fr ojm the die 2 6 to complete a single riveting; operation. The adjacent ends of the le-wer'die 2 5 an d a n upper'die 21, within the lower; end ofthe plunger, are concave in'shape inordeif that the ends-or the rivet may havean even rounded form whe'n headed; A spring 28 mountedwithin the easing" I2 in'a manner not herein shownjis donnected'to then-lovable jaw or plunger 24 and urges" itiipward' into engagement with the projection 23" on'l'ever'z l 'I'hroughthe plunger 24, 'th e spring" 28' acts also to main tain the upper edge of the lever M inf c'on'tactwith the lower" one of the pair ofrollers 181 The upper edge of the lever 21 1s formed with a depression 29 near the pivot point 22 and with an inclined surface 3| extending from a, point near the depression 29 to the outer end of the lever.

With the piston in retracted position, or in 3 the lefthand end of the cylinder II as viewed in Fi 1, the lower roller is takes a position above the depression 29 allowing the lever 2| and plunger 24 to rise from the fully operated position of Fig. 1 to a normal position wherein the dies 26 and 27 are spaced apart a suffieient distance to permit the application of the tool to the next rivet. As the piston l4 moves forwardly, or to the right as viewed in Fig. 1, the rollers l8 pass between the lever 2| and guide block I9 and act as a. wedge, moving the lever 2| in a clockwise direction and thereby forcing the plunger 24 downward toward the die 26. At the of a hose line 4|, from a source (not shown) to an inlet passage 42 formed in an extension 43 start of the forward or compression stroke the lower roller l8 rides out of the depression 29 and, in so doing, moves the lever 2| and plunger 24 quickly through the major portion of their travel toward fully operated position. This initial movement of the plunger brings the die 21 into contact with the work and is usually termed the rivet setting portion of the stroke. As the piston |4 continues to move forwardly the lower roller l8 advances along the slightly inclined surface 3| and the plunger 24 is pressed down slowly to the position shown in Fig. 1, completing the rivet heading operation.

The upper edge 3| of the lever 2| is substantially a straight line for the major portion of its length. Toward the front end, however, it has a slight curve, upwardly and forwardly. The shape of the edge 3|, which may be determined either empirically or mathematically, is preferably such as to prevent substantial variation in the mechanical advantage, or instantaneous speed ratio, between the primary power piston l4 and the working plunger 24 during the final travel, say, the last one-eighth inch, of plunger 24. As a result, the maximum, or final, riveting pressure will be proportional to the maximum or ultimate cylinder air pressure, notwithstanding variations of, say, one-eighth inch, in the thickness of the plates being riveted together.

The front of the end portion, or casing, I2 is closed by a plate 32, which supports an adjustment means whereby the distance which the dies 26 and 2'! are spaced apart in the normal position of the plunger 24 may be varied to compensate for differences in the length of the rivets or the thickness of the sheets being joined. This adjustment means comprises a settable element or member 33 having a stem extending into a bracket 34 secured to the outside surface of the plate 32. A thumb nut 35, supported by the bracket 34- and plate 32, has a threaded engagement with the stem of the element 33 and by manipulation of the thumb nut the settable element may be raised or lowered relatively to the bracket 34. The lower end of the element 33 extends inwardly through a slot in the plate 32 and has mounted therein a plunger 36 pressed, by means of a spring 31, toward the outer end of the lever 2 I. If it is desired at times to temporarily relieve the settable element33 from engagement with the plunger 24 without affecting its original setting, the stop plunger 36 contained in the element 33 is withdrawn against the action of its spring 31, whereby the main plunger 24 can pass upwardly beyond the stop plunger 36. The end of the plunger 36 is positioned above a cutout portion 38 in the upper end of the plunger 24 and is adapted to engage this cut-out portion to ,of the head I0, which extension serves as a handle for the tool. The passage 42 opens into a bore 44 in the head I0 and the air flowing 'into the bore 44 is admitted, under the control *of a throttle valve 45, to a compressed air distributing system whereby it is caused, upon actuation of the valve 45, to drive the piston l4 forwardly and, when a predetermined peak pressure is reached within the cylinder II in back of the piston M, to return the piston to normal position. In Fig. 1, the throttle valve 45 is shown in open position and the piston 14 at the end of its compression stroke.

What is claimed is:

In a mechanical movement having a movable member a return stroke adjuster adapted for controlling the extent of movement of the member in successive forward and return strokes, said stroke adjuster comprising a plunger resiliently maintained in a first position to engage the movable member to restrict full return stroke movement thereof and manually operable to a second position which will allow the movable member unrestricted and full return stroke movement, and an axially adjustable means for the mounting of said plunger, said axially adjustable means having a first part, one end of which houses said plunger, the other end of which has an external screw-threaded surface, and a second part comprising a thumb nut which operatively engages said screw-threaded surface and is positionally maintained for rotational movement whereby said first part may be moved in either direction along an axis parallel to the direction of movement of said movable member.

HOWARD R. FISCHER.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 484,360 Gawley Oct. 11, 1892 496,059 Loss Apr. 25, 1893 582,839 Winans May 18, 1897 884,548 Warwick Apr. 14, 1908 1,781,156 Brown Nov. 11, 1930 1,942,414 Dumser Jan. 9, 1934 2,082,334 Harcount June 1, 1937 2,109,162 Boshle Feb. 22, 1938 2,203,608 Wood June 4, 1940 2,310,556 Strong Feb. 9, 1943 FOREIGN PATENTS Number Country Date 777,228 France Nov. 26, 1934 812,962 France Feb. 15, 1937 

